Aetiology of work-related disorders of the rotator cuff tendons: Research and theory

Can COVID-19 infection be considered an occupational disease or injury? Analysis to fill up regulatory gaps

BACKGROUND

Although the pandemic is nearing its end, the question of whether COVID-19 infection will be considered a work-related or occupational disease remains a legal issue. Therefore, this study aims to provide clarification on this matter.

OBJECTIVES

Since the International Labour Organization (ILO) serves as the primary authority on work-related matters, this study is focused on analyzing the ILO's policies regarding the acknowledgment of COVID-19 infections as occupational diseases. It also investigates how States can recognize COVID-19 as such a disease while delving into the connection between the disease or injury and the occupation itself.

METHODOLOGY

This study utilizes a doctrinal methodology, focusing on legal research. This approach employs an applied (expository) research method and discusses the topic from a professional constituency perspective, as proposed by Arthurs in 1983.

RESULT

The findings indicate that the ILO does not explicitly mention the pandemic or COVID-19 infection as an occupational disease in its list. However, it does include "infectious-related diseases" or "work that carries a particular risk of contamination" as occupational or work-related diseases, which can logically be interpreted as encompassing COVID-19 infection as an occupational or work-related disease.

RECOMMENDATION

As the ILO sets guiding principles for its member States, this study recommends that the ILO should establish clear and comprehensive guidelines for member States to recognize COVID-19 infections or any future pandemics as occupational diseases.

CONCLUSION

This study will serve as a valuable resource for policymakers who intend to enact or amend national legislation to align with the ILO. Furthermore, it will assist relevant stakeholders in taking necessary actions based on the study's findings.

Sex Differences in Rotator Cuff Muscles' Response to Various Work-Related Factors

Occupational ApplicationsDespite the frequency and cost of rotator cuff injuries among male and female workers, very little is known about the strength, endurance, and perceived exertion and electromyographic response of rotator cuff muscles to different exertion levels. In this study, sex differences were studied using muscle-specific maximal and submaximal exertions of the supraspinatus, infraspinatus, and teres minor muscles. Females showed lower strength and endurance, but higher muscle activity and perceived exertion compared to males. The baseline data presented in this paper can assist ergonomic practitioners in determining the worker capacity to ensure that physically-demanding shoulder exertions can be performed without incurring injurious stress. Such data is also essential to establish population norms for the better design of workplace tasks.

Relationships between maximum holding time and ratings of pain and exertion differ for static and dynamic tasks

Ratings of perceived discomfort (0 to 10 scale) have been used to estimate relative maximum holding times (%MHT), particularly for static tasks. A linear 1:10% ratio has been described, where a rating of 5 corresponds to 50%MHT. It is unknown whether this linear ratio is valid for dynamic tasks. Additionally, whether pain or exertion are the primary predictors of discomfort is not clear. Thus, the goal of this study was to investigate both pain and exertion ratings during static (50% maximum; N=42) and dynamic (75% maximum; N=34) elbow flexion tasks until failure. Gender, self-reported physical activity, and peak torque were also assessed. Pain and exertion ratings reasonably matched the 1:10% ratio during the static task but not during the dynamic task. Exertion related more strongly to MHT than pain in both tasks. Neither gender nor activity level appeared to influence perceptual ratings, but peak torque explained approximately 20% of the variance in MHT.

The evolving role of biomechanics in prevention of overexertion injuries

This paper describes occupational biomechanics as an evolving body of knowledge that has required not only a sophisticated development of fundamental biomechanical principles and human failure data, but also has required epidemiological information to enable a more complete understanding of how certain types of musculoskeletal injuries can be caused by specific physical work requirements. It also is argued that even with adequate biomechanical and epidemiological information, the ability to change working conditions and manual task requirements in companies required management and workers to become organised into formal ergonomics teams that could be trained and empowered to reduce the known biomechanical risk factors present in various jobs. It is demonstrated that in the last 35 years occupational biomechanics research continues to provide the intellectual machine that is driving the development of important ergonomics guidelines. Despite these successes, however, some major limitations in contemporary biomechanics knowledge are discussed, particularly related to situations where high-speed motions and repetitions are involved. Finally, the evolving importance and limitations in occupational biomechanical simulation models for proactive ergonomics are presented.

Fatigue during prolonged intermittent overhead work: reliability of measures and effects of working height

Shoulder pain is prevalent among industrial workers and existing evidence supports that overhead work is an important specific risk factor. Existing guidelines are limited, with overhead work typically recommended to be avoided, and research on overhead work has been mixed in terms of the effects of increasing arm reach. A laboratory-based simulation of overhead work was conducted, at three working heights, in order to facilitate improved guidelines and to identify potential non-linear effects of overhead work height. Several indicators of shoulder fatigue served as outcome measures and a preliminary study was performed to assess the reliability of several of these measures. Fatigue measures based on electromyography (EMG) generally had low reliability, whereas excellent reliability was exhibited for ratings of perceived discomfort (RPD). Consistent with this, no effects of overhead work height were found on EMG-based measures, yet clear non-linear effects were found on RPD and task performance. The source of the effects of work height appeared to be related to a combination of muscle activation levels and demands on precision/control at the highest location. These results support the utility of subjective measures for relatively low-level intermittent exertions and demonstrate increasingly detrimental fatigue and performance effects at extremes in reach during overhead work.